The travel of the head is what will dictate the width of board you can cut, and they’re not all the same. You should be able to find specs online for any machine, new or old, that you’re considering. In theory the 12” saw with the same travel will have less width capacity due to the fact the fence would have to be 1” closer to you to make up for the blade’s larger radius. I ran into this problem years ago putting the correct 18” blade on an old DeWalt from a 14” blade that we had at the time. While I could now cut through 6”x material, the fence had to be moved 2” closer to the operator due to the increased blade radius. One other thing to think about is what blades are in your shop now? I’ve got over 40 10” blades and zero 12” blades, if I were to pick up a RAS it would make sense for it to be 10”.

There are a bunch of them out there. This one is 12 inch, with a 110/220 motor. Another thing to consider, what about the arbor size? I can’t find any info on it. If it is 1” does that mean that I could not use the 5/8 arbor blades. I am mainly thinking about the holes on my dado blades.

I own and like the 7790. I use a spacer to take the 1” arbor down to the 5/8 size. They sell spacers exactly for this purpose and they are suitably cheap (like 10$ or less).

Blade travel depends on the saw not the size of the saw if that makes sense.

Either way a RAS is only as good as the table. Just putting down some hardwood or plywood will produce pretty terrible cuts in short order. Search Mr Sawdust Table. There are instructions available to build a reusable and truly fantastic table.

Here’s my restored 1952 Rockwell/Delta Multiplex 40-B, it takes 12” or 14” blades and she will cross cut 16” of 1-1/16 thick stock with the 12” Forrest Chopmaster blade I have installed now. Table is 24”x48” a sandwich of 3/4 ply with a Sapele hardwood center. I clamped and pressed this table down flat onto my table saw table with lots of weight so its quite flat but if I had to do it over I would have used Russian Birch ply vs the Lowes junk. Still it came out nice I’m happy with it.

Last night was my first attempt at dialing it in and making a test cut. Across a 4 inch board I’m .003 out of square, vertically I’m about .002 out of square so I have a touch of adjustment yet to perform. Dang the thing is a bit intimidating at first that big blade really spins. It cut the Sapele like it wasn’t there.

That Dewalt is one of the more excellent saws available. You cannot do better. Once tuned, it will cut with laser accuracy, and return to 90º with precision after you swing the arm around. The key is the solid cast iron arm, later models were “value engineered” and much of the precision was lost. Should you buy it, I have a pdf file that would be of use in tuning it, I can e mail it if you want/need.